Reticulated mat assembly



March 30, 1943. 4 H. NAGIN Erin; 2,315,443

RETICULATED MAT ASSEMBLY Filed Oct. 18, 1940 s Shetseat 1 March 30,1943; H, NAGIN ETAL; 2,315,448

RETICULATED MAT ASSEMBLY Filed Oct. 18, 1940 -s Sheets-Sheet 2 ,Marchso,1943. H. mam AL 2,315,448

RETICULATED- MAT ASSEMBLY Filed 00%..18, 1940 s SheetS SheQt s lea)? MPatented Mar. 30, 1943 RETICULATED' MAT ASSEBELY Harry Nagin and LeonNagin, Pittsburgh, Pa., as-

signors to Reliance Steel Products Company, McKeesport, Pa., acorporation of Pennsylvania Application October 18, 1940, Serial No.361,806

6 Claims.

This invention relates to the construction of reticulated mat assembliesand, more specifically, to the construction of landing mats for use asaeroplane landing fields on otherwise unuseable terrain.

It has been heretofore proposed to construct landing fields byassembling a plurality of reticulated units to form a landin stage. Allsuch devices, however, with which we are familiarhave the disadvantageof being difficult to assemble, and in event of destruction of one ofthe units of the mat in any way, its replacement either requirsconsiderable time and labor or is substantially impossible.

An important object of this invention is the provision of a mat of thischaracter which may be very readily and cheaply manufactured, andrapidly assembled and disassembled.

' A further and more important object of the invention is the provisionin a construction of thi character of an arrangement such that anyindividual unit of the mat may be removed and replaced immediatelywithout disturbing any of the surrounding units.

A still further object of the invention is the provision of a novel andimproved method of interconnecting the units of the completed mat.

These-and other objects'we attain by the construction shown in theaccompanying drawings wherein, for the purpose of illustration, we haveshown a "preferred embodiment and wherein: 7

Fig. 1 i a send-diagrammatic perspective view showing "a landing matconstructed inaccordance with our invention;

Fig. 2 is a fragmentary plan view of a mat illustrating themethod ofassembly;

Fig. 3 is a section on line 33 of Fig. 2;

Fig. 4 is an enlarged detail plan view of aportion :of the mat structureshowing the method of aligning and connecting the units;

Fig. 5 is an enlarged perspective view showing two adjacent units and.illustrating the construction of the side and end members;

, Fig. .6 .is a fragmentary perspective view showing the construction ofthe opposite end of the mat from that illustrated in Fig. 5;

Fig. '7 is a perspective view of one of the wedge fasteners employed;

Fig. 8 is an enlarged detail sectional view illustrating the manner ofuncoupling or coupling the mat units in event of damage to one thereof;

Fig. 9 is a section on line '9-9 of Fig. '4; and

Figs. 10 and 11 are detail perspective views of our inventionillustrating various methods of reinforcing the bars at thewedge-receiving slots thereof.

Referring now more particularly to the drawings, the numeral itgenerally designates an individual unit of the completed mat, a portionof which is illustrated diagrammatically in Fig. 1 of the drawings. Eachunit i preferably rectangular in form and comprises a side and an endmember, I I and I2 respectively, formed of flat bar steel and which are,at spaced intervals, offset inwardly, as indicated at is, these offsetportions being formed to provide a fiat seat H! which is perforated, asat l5, to receive the shank Id of a wedge element which is permanentlylocated in the opening of the seat and has at one end a fixed polygonalhead I! for engagement by a wrench and at its opposite end a wedge headIt, the extent of the offsets [3 being such that the wedge head I8 maybe completely located within the offset, for a purpose presently toappear. The wedge head I 8 has flat parallel sides I 9 which arepreferably substantially co-planar with the walls of the shank, whileits end faces 20 diverge sharply and oppose the polygonal head H.

The remaining side and end members, indicated at 2! and 22 respectively,are likewise composed of fiat bars, and these end members have .slots 23of a width to receive a wedge head [8 of the opposed side or end memberI6 or I l of associated units. The shank I6 of the wedge element is ofsuch length that when the head I i is seated upon seat i l, the wedgesurfaces 20 are positioned to have wedging engagement with the sideedges of slot 23 when the Wedge element :is rotated, this wedgingcausing a slight spring- 'ing of the bars H and 21, or l2 and 22 andaffording a secure connection between the sides and ends of the adjacentunits. In order to avoid too extensive springing of the bars 2! and 22,which naturally will be weakened by the formation of the slots 23therein, these bars may be suitably reinforced at or adjacent the slotin any suitable manner. In Fig. 10 we have shown the edges of the slotas slightly swedged at 23a to provide a reinforcing rib about the edgesof the slot, while in Fig. 11 we have shown the bars 2| and 22 aspressed at 2% to form longitudinal ribs thereon paralleling the slots atopposite sides thereof.

To assist in aligning mat sections i0 during assembly so that the wedgeelements of one section will be properly related to the slots ofassociated sections, an end bar of each section is formed in its upperedge with a notch 24, and the side bars of the section have theirterminals,

at the opposite end from the notched end bar, formed as projecting hookportions 25 to engage in the notches 24 of an associated section. Thebills of the hook portions 25 have their inner faces curved outwardly,as indicated at 26 so that these hook portions may be disengaged for apurpose presently to appear.

The end members l2 and 22 of each unit are connected by a series ofparallel bearing bars 21 which may well be formed of the same materialas that from which the side and end members are formed. The side membersH and 2| are connected to one another and to the bearing bars 21 bytransversely extending cross bars 28 which may be conveniently formedfrom round bar stock, as shown. These cross bars have their uppersurfaces substantially coplanar with the upper surfaces of the bearingbars and side and end bars; and the bearing bars, cross bars, and sideand end bars are welded to one another at all points of contact, asindicated. The lower edges of the side members and bearing bars may bebonded to one another by tie rods 29, these tie rods being installed inthe same manner as the cross bars 28 and serving to further rigidify thestructure.

In assembling a landing mat from units of this character, a single unitis placed upon the ground, following which two units are placed againstthe (previously laid unit with the end members l2 thereof in engagementwith the end member 22 of the original unit, the hooks 25 at adjacentsides of the last-laid units being engaged in the notch 24 of theoriginally laid unit. This will bring the wedge fasteners of thelast-laid units along adjacent side members thereof into alignment withthe slots 23 in which they are to engage, it being understood thatduring the assembly the wedge elements are withdrawn into the offsets [3so that they will not interfere with proper laying of the units.Similarly, portions of the wedge fasteners at the ends of the lastlaidsections will be aligned with the slots in the end member 22 of theoriginally laid section. The sections are then fastened together by thewedge fasteners and other Sections similarly positioned until thelanding mat is complete.

In event a unit of the landing mat is damaged to an extent requiring itsremoval, this may be readily accomplished by releasing the wedgefasteners of the damaged unit and then elevating that end of the unithaving the end member 12. The bills of the hooks of the units engagedwith the opposite end of the damaged unit will then serve as pivotsabout which the unit may be rotated to disengage the same by continuingthe elevation until the damaged unit is completely disengaged from thehook, following which it may be removed by shifting the same in thedirection of the arrow in Fig. 8. Through a reversal of this process, afresh section may be inserted in the gap thus formed.

Obviously, a mat of this character is subjected to rough usage, beingsubjected to impact in the landing and launching of aeroplanes and inmany cases to the necessary passage thereover of laden vehicles, such asambulances, fuel supply trucks, etc. The resultant vibration may, insome cases have a tendency to cause loosening of the wedge locksemployed, and for this reason some means is preferably provided forresisting rotation of these looks from their locking position. This maybe readily accomplished by providing seats H with projecting shallowribs Ma which will oppose a facet of the head when the locking member isin its locking position and, accordingly, prevent rotation of thelocking member which will be held in engagement with the surface of thehead through the spring action resulting from the pressure engagement ofthe wedge head 18. These ribs may be made sufficiently shallow so thatthey will not offer undue resistance to rotation of the wedge locks totheir operative position.

Since the construction illustrated is obviously capable of considerablemodification without departing from the spirit of our invention, we donot wish to be understood as limiting ourselves thereto except ashereinafter claimed.

We claim:

1. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable rotatable fastener elements permanentlyassociated with said side members and each including an irregularlyshaped fastener head disposable in one of said coves and within theconfines of the unit, the remaining side members of each unit havingopenings for the passage of the heads of the fasteners of associatedunits, a side member of each unit having at the upper portion thereof arigid downwardly facing projecting hook portion adapted for engagementin a notch in a side member of an associated unit, said hook portionshaving rounded bill elements permitting disengagement of associatedunits by rotation of a given unit about the bill portion of the hook ofan associated unit as a pivot.

2. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable rotatable fastener elements permanentlyassociated with said side members and each including a wedge-shapedtransversely elongated fastener head disposable in one of said coves andwithin the confines of the unit, the remaining side members of each unithaving elongated slots for the passage of said heads, and means on eachunit detachably engaging an associated unit for aligning the fastenerelements of each unit with the coacting means of associated units.

3. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable rotatable fastener elements permanentlyassociated with said side members and each including a wedge-shapedtransversely elongated fastener head disposable in one of said coves andwithin the confines of the unit, the remaining side members of each unithaving elongated slots for the passage of said heads, a side member ofeach unit having at the upper portion thereof a rigid downwardly facingprojecting hook portion adapted for engagement in a notch in a sidemember of an associated unit. said hook portions having rounded billelements permitting disengagement of associated units by rotation of agiven unit about the bill portion of an associated unit as a pivot.

4. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable axially rotatable and longitudinally shiftablefastener elements permanently associated with said side members and eachincluding a wedge-shaped transversely elongated fastener head disposablein one of said coves and within the confines of the unit by longitudinalshifting of the element, the remaining side members of each unit havingelongated slots for the passage of said heads, and means for yieldablymaintaining said heads in position when the same have been rotated to aposition transverse to the associated opening.

5. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable axially rotatable and longitudinally shiftablefastener elements permanently associated with said side members and eachincluding a Wedge-shaped transversely elongated fastener head disposablein one of said coves and within the confines of the unit by longitudinalshifting of the element, the remaining side members of each unit havingelongated slots for the passage of said heads, means for yieldablymaintaining said heads in position when the same have been rotated to aposition transverse to the associated opening, and means on each unitdetachably engaging an associated unit for aligning the fastenerelements of each unit with the coacting means of associated units.

6. A landing mat comprising a series of detachably connected units, eachunit comprising a polygonal grate having side members and having anadjacent pair of said side members provided with coves in their outerfaces, quick-detachable rotatable fastener elements permanentlyassociated with said side members and each including a wedge-shapedtransversely elongated fastener head disposable in one of said coves andwithin the confines of the unit, the remaining side members of each unithaving elongated slots for the passage of said heads, and means foryieldably maintaining said heads in position when the same have beenrotated to a position transverse to the associated opening, a sidemember of each unit having a projecting hook portion adapted forengagement in a notch of a side member of an associated unit, said hookportions having rounded bill elements permitting disengagement ofassociated units by rotation of a given unit about the bill portion ofan associated unit as a pivot.

HARRY NAGIN. LEON NAGIN.

